Source: 18th Battalion Nominal Roll (April 1915).
Find-A-Grave
May have immigrated to United States 11 February 1921.



From a cached website:
Sidney Clarence Featherstone1
M, #60796, b. circa 1888
Father* William Featherstone b. c 1863
Mother* Helen Mason b. c 1863
Sidney Clarence Featherstone was born circa 1888.1 He was the son of William Featherstone and Helen Mason. Sidney Clarence Featherstone married Annie Rhoda Ada Martin on 23 December 1914 at St Marys, Perth, Ontario, CanadaG.1
Family
Annie Rhoda Ada Martin b. c 1896
Last Edited 7 Jul 2014
Reference 738
Citations
[S2061] Unknown author Family Search, Url: http://www.familysearch.org “Name: Sidney Clarence Featherstone Event Type: Marriage Event Date: 23 Dec 1914 Event Place: St Marys, Perth, Ontario, Canada Age: 26 Birth Year (Estimated): 1888 Father’s Name: William Mother’s Name: Helen Mason Spouse’s Name: Annie Rhoda Ada Martin Spouse’s Age: 18 Spouse’s Birth Year (Estimated): 1896 Spouse’s Father’s Name: Arthur Spouse’s Mother’s Name: Connie Peirey Page: 018412 Digital Folder Number: 004705221 GS Film Number: 002022058 , Image Number: 00859 ‘Ontario Marriages, 1869-1927,’ index, FamilySearch(https://familysearch.org/pal:/MM9.1.1/278Q-SLF : accessed 07 Jul 2014),Sidney Clarence Featherstone and Annie Rhoda Ada Martin, 23 Dec 1914;citing registration 018412, St Marys, Perth, Ontario, Canada, Archivesof Ontario, Toronto; FHL microfilm 002022058.”